The recent increase in telecommunications network connected devices, such as FAX machines, pagers and personal computer modems has increasingly lead to telephone number exhaustion. Telephone number exhaustion occurs when substantially all of the telephone numbers in a given numbering plan area (NPA), also known as area code, have been assigned to active customers and are no longer available to new customers. Local telephone operating companies, known as Local Exchange Carriers (LECs) deal with telephone number exhaustion by assigning new area codes to existing customers, effectively "splitting" an area code. At present, over 75 area codes have been split and some have been split twice. This phenomenon is occurring not only in the United States, but in other countries as well.
When an area code is split, some of the existing customers in the area code are assigned to a new area code. These reassigned customers are given a new telephone number, which consists of the new area code, followed by the customer's existing three digit exchange code and four digit subscriber code. Callers who dial a customer's telephone number after the split occurs receive a message indicating only that the call can not be completed. No announcement of the split is provided and the call is not completed. This causes inconvenience to callers, who cannot complete their calls, and to called parties, who miss the calls that were not completed. It also causes lost revenue to telephone carriers, which incur call setup expenses, but cannot charge for uncompleted calls. A more effective caller notification technique is needed.
Customers whose telephone numbers will change due to an area code split may inform potential callers of the change in advance of the split. Currently, customers are notified via the telephone bill and by television, radio and newspaper advertisements. Often customers fail to communicate such notification because time has elapsed and they simply forget about it. A more effective customer notification technique is needed.